Ion Investments, which is controlled by Singapore’s sovereign wealth fund Temasek Holdings, has sold a part of its stake in South Korean biopharma company Celltrion and its distribution unit Celltrion Healthcare in a block deal worth around 1.1 trillion won ($1.03 billion).

News of the deal, which was made after the market’s close on Tuesday, led to the price of Celltrion and Celltrion Healthcare plunging by more than 10 percent Wednesday.

According to news reports, Temasek on Tuesday pushed a block deal selling 2.24 million shares (1.8 percent) in Celltrion for 336,700 won, and 2.9 million shares (2.1 percent) in Celltrion Healthcare for 108,654 won to institutional investors.

The pricing represented a discount of 9 percent from Tuesday’s closing stock prices of Celltrion and Celltrion Healthcare. Through the sale, Temasek retrieved around 1.1 trillion won in gains.

Amid investor concerns over Temasek’s move, Celltrion released a statement Wednesday noting that the Singapore fund had clarified the purpose of the sale was to “rebalance its investment portfolio” and that “its position as a longtime investor in Celltrion and Celltrion Healthcare remains unchanged.”

“Celltrion will continue to strengthen its partnership with Temasek, a longtime financial investor which has shown continuous trust and interest (in Celltrion’s business),” it added.

Following the block deal, Temasek still holds a 12.44 percent stake in Celltrion, retaining its position as the drugmaker’s second-largest shareholder after Celltrion Holdings.

In Celltrion Healthcare, Temasek retains a 10.4 percent stake, making it the third-largest shareholder after Celltrion’s founding Chairman Seo Jung-jin and JP Morgan-owned One Equity Partners.

Together, the current value of Temasek’s net take in Celltrion and Celltrion Healthcare reaches around 7 trillion won.

Based in Songdo, Celltrion specializes in making biosimilars -- cheaper, near-replicas of biologic drugs whose patents have expired. It currently sells biosimilars referencing blockbuster biologics including Remicade, Rituxan and Herceptin.

Celltrion Healthcare is the marketing and distribution unit of Celltrion.

On Wednesday, Celltrion also reshuffled its top executives, in what it said was a move to strengthen its footing in global markets. Ditching its dual-CEO structure, Celltrion named Kee Woo-sung the sole chief executive while tapping Kim Hyoung-ki as the new head of Celltrion Healthcare.

In addition, Kee and Kim, whose current terms expire in March, have been promoted as vice chairman of Celltrion and Celltrion Healthcare, respectively. .By Sohn Ji-young (jys@heraldcorp.com)